JPH0519648A - Belt fixing device - Google Patents

Abstract

PURPOSE:To simply detach and attach the belt without necessitating a troublesome releasing operation or a complex tension releasing structure in the case of belt exchange. CONSTITUTION:An upper unit U1 is made by holding a first fixing roller 2 wound an endless belt 1 and a tension roller 3 at a first frame 10. Also a lower unit U2 is made by holding a second fixing roller 5 and the fixing roller pressing means 11, 12 pressing the second fixing roller 5 to the upper side at the second frame 13. The upper unit U1 is held to the lower unit U2 rotatably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt fixing device having an endless belt, and more particularly to a belt attaching / detaching structure of the belt fixing device.

[0002]

2. Description of the Related Art In a conventional belt fixing device provided with an endless belt such as a color copying machine, an endless belt wound between a fixing roller and a tension roller is
Since it was necessary to give proper tension to the belt so that it would not come off or slip during operation,
When assembling the product, it was fixed to the frame with tension applied by springs.

[0003]

However, in the conventional belt fixing device, it is necessary to release the tension of the belt with time and effort when exchanging the belt, which requires a very troublesome work. In addition, a complicated release mechanism is required to release the tension without trouble, and the device itself becomes large and the cost is greatly increased.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and a first fixing roller (2) and a downstream side of the first fixing roller (2) are provided. An endless belt (1) is wound around a tension roller (3) provided, and a second fixing roller (5) is wound around the endless belt (1) to form a first fixing roller (2). ), The first fixing roller (2) wound around the endless belt (1) and the tension roller (3) are held by the first frame (10). The upper unit (U1) and the second unit arranged on the downstream side of the first fixing roller (2).
The fixing roller urging means (11, 12) for urging the fixing roller (5) of the above and the upper unit (U1) are
Lower unit (U2) which holds the second fixing roller and the fixing roller biasing means (11, 12) in a second frame (13) while rotatably holding the fixing roller (2) in the second fixing roller (2). ) And are provided.

[0005]

According to the belt fixing device as described above, when the belt is exchanged, it is possible to easily detach the belt without requiring a troublesome tension releasing work and a complicated tension releasing mechanism.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a belt fixing device according to the present invention, FIGS. 2 to 4 are explanatory views of a belt tension releasing operation of the belt fixing device according to the present invention, and FIG. 2 is a schematic diagram showing a belt set state. 3 is a schematic view showing a state where the upper unit is released from fixing, and FIG. 4 is a schematic view showing a belt tension released state.

In the figure, 2 is a heat roller which is formed in a cylindrical shape and in which a heat source such as a halogen lamp is arranged. An endless belt 1 is wound around the heat roller 2 and a tension roller 3 arranged downstream of the heat roller 2. The surface of the endless belt 3 is formed of a film material such as a polyimide film coated with silicon resin or the like. The heat roller 2, the tension roller 3 and the endless belt 1 wound between the heat roller 2 and the tension roller 3 have the first frame 1 in which the shaft portions on both sides of the two rollers are the first frame 1.
It is rotatably held at 0 and 10.

The holes 4 and 4 for holding the shaft 3a of the tension roller 3 provided in the first frames 10 and 10 are
The direction of the heat roller 3 orthogonal to the axis 3a is the major axis (several mm
It has a long hole shape.

Further, the shaft portion 3a of the tension roller 3 is
Is provided so as to project outward from the elongated holes 4 and 4 of the first frames 10 and 10, and the shaft 3a is configured to be freely movable in the diametrical direction inside the elongated holes 4 and 4.

The movement of the shaft 3a is performed by the first frame 10,
It is regulated by springs 9, 9 provided on the outer side surface of 10. One end of each of the springs 9 and 9 has a contact plate 9
The first frame 1 is pressed against the shaft 3a via a and 9a.
It is pressed against the indicator plates 9b, 9b fixed to the outer surface of 0, 10. With this configuration, the tension roller 3 can be urged to the downstream side in the paper transport direction, and thus tension can be applied to the endless belt 1. For example, when the belt 1 is made of a sheet material of a polyimide film having a thickness of 50 μm, a tension of about 6 kg is required. The springs 9 and 9 are used so that In this way, the upper unit U1 is formed.

A pressure roller 5 is pressed against the heat roller 2 via the belt 1 below and downstream of the heat roller 2. The pressure roller 5 has its shaft portion rotatably held by the second frames 13, 13. The pressure roller 5 is brought into contact with a pressure contact lever 11, and the pressure contact lever 11 is biased upward by a spring 12. As a result, the pressure roller 5 is pressed against the heat roller 2.

The pressure contact lever 11 is rotatably supported by either one of the two left and right second frames 13, 13 and has one end at the end opposite to the shaft.
A spring having the other end fixed to the second frame 13 is provided.

The pressing lever is formed in a shape suitable for pressing the pressing roller 5 in the direction of the heat roller 2 with an appropriate nip width by the urging force of the spring 12.

The pressure contact roller 5 and the pressure contact lever 11 as described above.
Then, the spring 12 and the second frames 13, 13 constitute the lower unit U2.

The end portions of the second frames 13 and 13 on the heat roller 2 side are extended in the direction of the upper heat roller 2 and at the same height as the axis of the heat roller 2 at the heat roller 2. The shafts 15 and 15 are provided so as to project in the direction of the heat roller 2 (inward) in parallel to the shaft of the second roller.

On the other hand, at the positions facing the shafts 15, 15 at the end portions of the first frames 10, 10, the shafts 15,
Notches 10a, 10a with which 15 is rotatably engaged are provided.

With the above-described structure, the upper unit U1 can rotate up and down about the shafts 15 and 15 as a center of rotation, but it is fixed by a second frame screw or the like in a normal use state. (Fig. 2).

Next, the belt detaching operation at the time of exchanging the belt of such a belt fixing device will be described.

First, the screws on both side surfaces of the second frame 13 are removed to set the upper unit U1 in a free state, and then the unit U1 is lifted up. Then, the tension roller 3 part moves upward with the shafts 15 and 15 as the center of rotation, and the pressure bonding roller 5 accordingly moves the heat roller 2 and the belt 1.
Go away from.

At this time, the tension of the belt 1, which has been pressed by the pressure roller until then, is weakened and comes loose. However, since the tension roller 3 is slightly moved outward by the biasing force of the spring 9, the belt 1 does not slacken and come off (FIG. 3).

Further, FIG. 4 shows a state in which the upper unit U1 is lifted. When the upper unit U1 is lifted up to this point, the belt 1 is completely separated from the pressure roller 1. At that time, the belt 1 loses tension and is in a slack state.

In the above state, the upper unit U
It can be easily removed by removing 1 from the lower unit U2 and moving the belt 1 outward. To install a new belt to be replaced, the operation opposite to that for removing the belt may be performed, and thus the description thereof is omitted here.

With the above-mentioned structure, the belt can be easily replaced without requiring any complicated belt tension release mechanism.

[0024]

According to the belt fixing device of the present invention, the troublesome tension releasing work at the time of belt replacement is unnecessary,
Further, the belt can be easily attached and detached without requiring a complicated tension releasing mechanism.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a belt fixing device according to the present invention.

FIG. 2 is a schematic view showing a belt set state of the belt fixing device according to the present invention.

FIG. 3 is a schematic view showing a state in which the upper unit of the belt fixing device according to the present invention is released.

FIG. 4 is a schematic view showing a belt tension released state of the belt fixing device according to the present invention.

[Explanation of symbols]

1 Endless belt 2 First fixing roller 3 Tension roller 5 Second fixing roller 10 First frame 13 Second frame U1 upper unit U2 lower unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideo Matsuda             22-22 Nagaikecho, Abeno-ku, Osaka-shi             Within the corporation

Claims (2)

[Claims] 1. An endless belt is wound around a first fixing roller and a tension roller provided on the downstream side of the first fixing roller, and a second fixing roller is attached to the endless belt. In a belt fixing device in which pressure is applied from below a wound first fixing roller, an upper unit that holds a first fixing roller and a tension roller wound on the endless belt in a first frame, The second fixing roller disposed downstream of the first fixing roller
Fixing roller urging means for urging the fixing roller upward, and the upper unit rotatably held in the first fixing roller portion, and the second fixing roller and the fixing roller urging means. A belt fixing device comprising: a lower unit which holds the second frame on a second frame; 2. The tension roller for holding the tension roller has a hole shape of a long hole having a long diameter in the direction of the first fixing roller, and a tension roller for urging the tension roller in the paper discharge direction. The belt fixing device according to claim 1, further comprising a biasing unit.